Japan fell silent on Thursday afternoon to mark 10 years since the worst natural disaster in the country's living memory: a powerful earthquake, deadly tsunami and nuclear meltdown that traumatised a nation. A minute's silence was observed across the country at 2.46 pm local time (0546 GMT), the precise moment a 9.0 magnitude quake hit off the northeast coast on March 11, 2011, triggering a disaster that left some 18,500 dead or missing. bur-sah/rbu